1. Field of the Invention
The invention relates to the field of ski-supported vehicles. More particularly, the invention relates to snowmobiles equipped with wheels that will allow the snowmobile to travel readily over surfaces not covered with snow or ice.
2. Description of the Prior Art
Snowmobiles are vehicles that are constructed to travel across snow and ice. As is generally known, the snowmobile is driven by an endless drive track arranged at the rear end of the underside of the snowmobile. The front end of the snowmobile is supported and rides along two skis, which glide across the surface of the snow or ice. The skis typically have a carbide runner that runs along a portion of the bottom surface of the ski, to help keep the snowmobile traveling along a smooth track.
A disadvantage of snowmobiles is that the skis don't readily glide across gravel, hardtop, or other non-snow surfaces. This makes it difficult, if not impossible, to steer a snowmobile because the skis do not respond properly to the steering operations initiated at the handlebars. Quite often, the snowmobile needs to be dragged or pushed in driveways and across roadways, etc. Furthermore, when a snowmobile is driven or dragged across a non-snow surface, the carbide runners on the skis are subject to excessive wear and must be replaced more frequently, depending on how often a snowmobile travels across a non-snow surface. This inability to steer snowmobiles on surfaces other than snow and ice makes it difficult for people to maneuver their snowmobiles across roadways, driveways, onto ferries, etc.
In recent years, the sport of snowmobiling has changed evolved from one of traveling relatively short distances over trails close to home to one of weekend-long or longer cross-country trips. Previously, for example, a snowmobile operator would fill the gasoline tank of the snowmobile in his or her backyard, transport the snowmobile to a trail site or depart directly from the backyard for an afternoon or day of travel over snowmobile club trails, and then return home. Nowadays, people are traveling great distances across country on snowmobiles that involve two- or three-day tours or even such mammoth tours as from Alaska to Maine.
This development of the sport of snowmobiling into extended trips means that snowmobiles must now be refilled with gasoline and maintained while they are out traveling across open country. Thus, where in the past the tank on the snowmobile was filled at home or at the point of departure before a daylong excursion, snowmobiles now need to be refilled while out traveling. This means that the snowmobile must be driven to a service station, typically by traveling some distance along a road surface other than snow or ice. Also, now that such lengthy trips are being undertaken with snowmobiles, the presence of snow along the entire route is not guaranteed, and consequently, snowmobiles are being required more and more frequently to travel some distance across surfaces other than snow or ice. Before, when a snowmobile needed to be dragged or pushed only a short distance across a roadway or driveway, or up a ramp onto a ferry, it was possible for a person to do it alone or with the assistance of a traveling companion. Now, however, with the need to travel several miles along a roadway to get to a filling station, the inability to steer a snowmobile has become a major obstacle in the logistics and the enjoyment of the sport.
Efforts to make snowmobiles mobile on gravel or other surfaces have been undertaken over the years. Prior art includes conversion kits to replace the skis with wheels. These conversion kits were intended to replace the skis on a semi-permanent basis, that is, to convert a snowmobile into a wheeled vehicle for an extended period of time. Such conversion kits typically require that the ski be removed in order to mount the wheels, or, if the ski does remain attached to the vehicle, a longer kingpin must be used to mount the wheels. Thus, each time the wheels are mounted or removed, the kingpin must be replaced with the longer or shorter one, respectively. Both methods of converting the snowmobile to a wheeled vehicle involve a fair amount of work. Thus, such conversion kits are not generally an acceptable solution to the problem of having to change in relatively quick succession back and forth between a vehicle that rides on skis and one that rides on wheels, as happens when traveling over gravel or hardtop or other surface other than snow or ice to fill the gas tank or to load onto a ferry.
What is needed, therefore, are means for quickly converting a vehicle back and forth between one that glides on skis to one that rolls on wheels. What is further needed are such means that do not impair the steerability of the vehicle. What is yet further needed are such means that are easily implemented, without requiring great physical strength and without requiring the use of tools. What is still yet further needed are such means that are retrofittable on any conventional snowmobile ski.